DESCRIPTION (from the application): Individuals differ in the degree to which they experience acute and chronic stress. The negative effects of such stress on health, especially mental health, are well established. Individuals also differ in their perceptions of social connectedness. Persons who feel unconnected report being "lonely". Similar to stress, feelings of loneliness may have important negative effects on health. Furthermore, loneliness and stress may interact in their effects on health, so that loneliness impairs one? s ability to deal with chronic stress or to recover from stressful events. Theoretically, the social environment--household, family and neighborhood-- should affect levels of both loneliness and stress, although these relationships are relatively unexplored and poorly understood. Connections with family members should reduce loneliness and thus protect or improve health. Households provide the immediate context for individuals and bring with them both resources and demands. Imbalance in these resources and demands may influence stress, with consequent and subsequent ill effects on endocrine and immune systems and thus on health (see Projects 1 and 3). If households create the immediate context within which individuals function, households themselves are embedded in neighborhoods. A long tradition of research suggests that structural characteristics of neighborhoods shape the ways in which residents experience the neighborhood environment. Thus, the structural characteristics of the neighborhood may have important implications for individuals? perceptions of loneliness and stress. These perceptions may then in turn affect individuals? physical and mental health. We propose to examine the links between social environment, loneliness, stress, health, and disability among mature adults, in the framework of the conceptual model developed for this Program Project. We propose to use data from the Health and Retirement Study, a nationally representative, longitudinal survey of persons age 50 and above. We will use information from respondents? linked Medicare records to help characterize respondents? health. We will develop questions on loneliness, stress, and social support to be asked of a subsample of HRS respondents especially for this project. We will link characteristics of HRS respondents? census tracts to their individual data.